Germany coach Joachim Low insists his team must improve in the quarter-finals of Euro 2016.
The world champions cruised past Slovakia 3-0 to reach the last eight, where they will play either reigning European title holders Spain or Italy in Bordeaux on Saturday.
Jerome Boateng, Mario Gomez and Julian Draxler were on target for Germany, while they could also afford to miss a penalty, with Mesut Ozil's spot-kick saved by Matus Kozacik.
Low knows much stiffer tasks lie ahead and after the win in Lille on Sunday he told uefa.com: " Of course, like any other side, we've had our problems getting into the tournament because there are a lot of tactics in the group stage as teams can go through with three points.
"With all due respect to Slovakia, this is no pointer that we are going to dominate this tournament. We are still going to have to improve.
"In fact we have to improve if we want to have a say in this tournament. We can't give our opponents any space in the next game and we have to take our chances as we won't get as many.
"Both (Italy and Spain) are among the favourites; Italy are incredibly strong in defence and have a very good attack as we saw in the first two games. The Spanish have the best attacking game we've seen over recent years. The two sides differ but they are both real favourites."
Slovakia were never really in the match and barely threatened and coach Jan Kozak accepted that the better team won on the day, hinting that perhaps some of his players can expect to be left out of the next side he selects.
"They're a tournament side - they know when to start performing," he said. "I think they put in a great team performance and controlled the match. They deserved to win.
"Obviously any defeat is painful regardless of the opposition, but I think there's still a good feeling that we managed to get to the last 16 and play against the world champions.
"There were several players who weren't at their best. When two or three players aren't fully focused on the game and don't follow instructions exactly it's difficult to do anything about it. This match has opened my eyes and given me an insight into my players' characters so it's been very instructive."